Leveling instrument



Patented Mar. 1, 1921.

Q E S n m w m W.-BERKMN.

LEVELING INSTRUMENT.

APPLl-(IATION AFILED MAY 1,*.1920. 1,369,957.

unirse LEVELING INSTRUMENT.

PATE WILLIAM BERKMAN, OFCLEVELAND, OHIO.

Specification of Letters'Patent.

Patented Mar. 1,y l1921.

y Application filed. May 1, 1920.' Serial No. 378,250. p'

To all whom t may concer/n.:

Be it known that I, WILLIAM BERKMAN, a citizen of `the United States,- residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Leveling Instruments, of which the following is a specification.

My improvement in leveling instruments residesv more particularly in the balancing index member and the mode of mounting it within the leveling bar; in the demountable sighting elements used with the bar; and in the mitering blade which is pivotally seated within and at one end of vthe bar; all substantially as describedandclaimed, and as shown in the drawinoaccompanying this application, in which *igure 1 is a top plan view of my limproved leveling instrunient, and Fig. 2 is a side elevation thereof partly in section and showing a pair ofsighting members mounted thereon. Fig. 3 is a bottom plan view of the instrument7 and Fig. 4 is an enlarged cross section on line 4-4, Fig. 2. Figs. 5, 6 and 7 are perspective views of the three sections comprising the balancing index member, and Fig. 8 is a vertical section centrally through said sections assembled as in use. f Y l Y The instrument comprises a rectangular.

level or bar 2 of wood having separate metal end plates 3 and 4 aiiixed to its opposite ends'. The central portion of this bar has a round opening 5 extending transversely therethrough, and the outer ends of this opening at opposite sides of said bar are enlarged to provide retired iiat seats 7 adapted to receive and hold two graduated glass disks 8 in parallel and axial alinement. These glass disks are held firmly to their respective seats by rings of putty 9 or by any other suitable means adapted to be removed and replaced if the disks become broken and require repair.V Each glass disk has a shallow conical socket or cavity 10 centrally vwithin its inner face yor surface adapted to .provide a glass bearing for short pointed trunnions. on the opposite side edges of a flat tapering metal index blade l2. The opposite ends of this blade taper lto a sharp pointk and the central portion of the blade has parallel flat faces and a round opening therein situated below the axis as represented by trunnioiis 11. rl`his blade is always held in a perpendiffular or upright position by a balancing spirit tube consisting of two tubular sections 13 and 14, each of which is closed at its outer end and open and screw threaded at its inner end. @ne tubular section has a reduced externally-threaded extension 15 and an annular seating shoulder 16, and the other section has an internally-threaded open end 17 with an end seating'shoulder 18," whereby V said sections maybe screwed together with the index blade sleeved over extension 15 and tightly clamped between the respective shoulders on said sections, see Fig. 8. A i'iuid is placed within one of the sections before clamping the partsltogether and the index vmember thus built up is perfectly balanced and very sensitive and responsive in turning on its pivots in leveling operations,

and the instrument can be used for levelmitering or establishing a plumb line thcnigh `the agencyof the index blade and the gradua'tions on either glass disk. The

position of the index blade is visible at all Y times from either flat side of vbar 2, and the sharp end edge of the index blade may also be viewed through a round opening 19 and a glass disk 2O at the upper side edgeof theA bar. The simplicity of'this arrangement of parts makes the instrument inexpensive toY constructV and `to `maintain in repair; the

the short round stem 22 of a sighting ele- Vment is adapted to be inserted. One sighting member 23 has a straight edge 24 and the other member 2,5 is cupped and has a smallV sight opening 26 centrally therein. These 'sighting members may be bodily removed when Vnotin use.- The instrument-is further provided wit a mitering blade 27 having a` quadrant or rounded enlargement 28 at one end, andl this blade is adapted to be inclosed within a longitudinal recess 29 within one edge of'VA on one of the metal end plates 4 with the quadrant exposed to view. Gage marks on the side of this quadrant extend tangential bar 2 and to be clamped between ears 30 Y to its circular edge Vand are adapted to be f alined with the end face of plate l when the blade 1s turnedon its pivot clamping screw 3l. Vhen the blade is adjusted to any givengraduated glass dials, and by their joint use it is an easy matter to correctly measure the angle between two diverging or converging surfaces or to establish and tix the angular relation between two parts which mayor may not be joined together.

Vhat' claim is:

2. A lleveling instrument, comprising an index blade having trunnions and separate tubular balancing sections detachably secured thereto beneath the axis of said trunnionsv and adapted to contain a liquid.

2. A leveling instrument, comprising an index blade having trunnions and an opento be screwed together through said opening with said blade clamped between them.

1l. In a leveling instrument, a bar having a leveling index member and provided with a socket in one edge at each end thereof, in combination with separate sighting members having stems adapted to be'confined within said sockets, one of said members having a straight edge and the other member having a cupped portion with a relatively small sight opening centrally therethrough.

Signed at Cleveland, in the county of Cuyahoga, and State of Ohio, this 28th day of April, 1920.

WILLIAM BERKMAN. 

